Humidification system with air seal means



Sept. 176, 1947. o. J. KUENHQLD, SRh v2,427,531

' HUMIDIFICATION' SYSTEM 'WITH AIR SEAL MEANS Filed Nov. y1s, 1941 5 Asheets-sheet 2 S Si ATTORNEYS Sept- 16, 1947 o. J. KUENHoLQsR 2,427,531

HUMIDIFICATIO SYSTEM WITH'AIR SEAL MEANS Filed Nov. 13, 1941 5 Sheets-Sheet 4 m 1 *wf EM 56.9. :.14 TJ' L i 1 L? W 97'l l K ffl' ffm?v da! n f .zal

F/GJZ ATTORNEYs Sept. 16, 1947l 0.11. KUENHOLD, sR

HUMIDIFICATION SYSTEM WITH AIR SEALMEANS Filed Nov. 13, 1941 5 Sheets-Sheet 5 INVENTOR ATTORNEYS M Mad Patented Sept. 16, 1947 ,irren Ni'rso s'ries 'r 'r HUMIDHFECA'IION SYSTEM WITH AIR SEAL MEANS Application November 13, 1941, Serial No. 418,926

18 Claims. (Cl. 126-113) l 2 My invention relates to humidication, partems is largely water, and for purposes of this ticularly to humidication systems and apparadescription, the source of liquid may be a water tus for use with furnaces, especially hot air supply pipe 29,;1eading from a city water supfurnaces, and the principal object of my invenply, or from `a well or the like. From the pipe tion is to provide new and improved humidica- 29, the water passes through, a shut-off valve tion systems and apparatus. 2i, and then througha water filter 23, of any This application is a continuation in part ci suitable construction, the filter being for the copending application serial Number 263,265, purpose of iltering out impurities suspended in iiled March 21, 1939, and a continuation infpart the water. The filtered water then passes of my copending application Serial Number through ya pressure regulator 2t, of any suitable 263,266, filed March 2l, 1939. construction, but preferably of the construction In the .drawings accompanying this specicashown in my patent, Number 2,249,010. As distion and forming a part ofthis applicatiomthere closed in such patent, the pressure regulator 2d shown, for purposes of illustration, various is provided with a manually operable purge lever embodiments which my invention may assume, Z5,Y whichv when twisted in either direction, fully and in these drawings; opens the valve regulating the water pressure, so Figure l is a generally schematic View showing that water under full pressure is admitted to the a humidiiication system embodying my invensystem, for a purpose to be hereinafter pointed tion, out. Under normal operating conditions, it is Figure la is a schematic View of a detail. preferable that the pressure regulator is so set Figure 2 is an enlargedelevational view oi a that it delivers water-to the humidication sysdevice used the system shown in Figure i., tem at a greatly reduced constant pressure.

Figure 3 is a vertical sectional view corre- Ajconduitii leads from the outlet port of the spending generally-to the line 3 3 of Figure 2, pressure regulator 24, and extends to the inlet Figure 4 is a top plan View of the device shown 25 of a water-feed control device 21. A conduit 28 in Figure 2, leads from the outlet of the water-feed control Figure 5 is an enlarged elevational view of device 21 to the inlet of a water-feed device 29, another device used in the system shown in and the latter device has adra-in conduit lead- Figure 1, ing to a suitable drain.

Figure 6 is a vertical sectional view correspond- 30 The water feed devicehas a conduit -Sl proing generally to the line 6 6 of Figure 5, viding liquid communication between it and an Figure 7 is a transverse sectional View corevaporator means, here shown in the form of responding generally to the 'line l-l of Figure 6, an elongated evaporator pan 32 having evapo- Figures 8 and 9 are generally schematic views rator plates 33 extending upwardly out of the showing other humidication systems embodywater in the evaporator pan 32. The evaporator ing my invention, pan 32 and the evaporator plates 33 are disposed Figure 10 is an enlarged elevational view of a within a chamber 34 through which air'may device used in the system shown in Figure 9, move. The chamber 34 may comprise part of a Figure 11 is a vertical sectional View correheating system, and in this instance is adapted sponding generally to the line II-ll of Figure for the passage of heated air to a place in a l0, dwelling to be heated. Since the air in the Figure 12 is a generally schematic view shoW- chamber 34 at times is of different temperatures, ine another humdication system embodying the air pressure in the chamber 34- will vary, at my invention, least partly because of expansion and contrac- Figure 13 is anenlarged vertical sectional View 45 tion of the air, of a' device used 1n the system shown 1n Figure '12, The humdcaton system Shown in Figure 1 Flgure 14 1s a top plan VIEW of the devl is particularly designed for cooperation with a shown in Figure 13,

Figure 15 is a fragmentary vertical sectional View corres ondin enerall to the line l5-l5 50 of Figure l andg g y tion of the furnace and up mto the bonnet cham- Figure 16 is a transverse sectional View correber from whence it is distributed by risers to Sponding generally to the une |5 5 of Figure 13 the rooms to be heated. Of course, the air blower,

Referring particularly to Figure l, the System ina properly designed and installed furnace, cptherein shown is connected to a source 0f liquidn 55 erates-intermittently and forces air past the heat- The liquid ordinarily used in hum-idication sysing portion of the lfurnace and to the bonnetv hot air furnace of the type employing an air blower operable to force air past the heating poralia/,esi

chamber only whenheat is called for. Therefore, intermittent operation of the air blower causes sharp fluctuations in air pressure in the bonnet chamber, due at least partly to the inertia of the air in such chamber, and to the resistance to air flow in the risers. In hot air furnaces, the chamber 34 is preferably the bonnet chamber, In accordance with my invention,` the system includes a pressure-equalizing means 35 extending between the water feed device 29 and the chamber 34, for a purpose hereinafter explained;

Blower means operable when heat is called for, and arranged to force air into and through the chamber 34, is shown schematically in Figure la. It will be understood that the illustration in Figure 1a is merely one of numerous possible embodiments.

Referring particularly to Figures 2 through 4, the water-feed control device 21 comprises a cup 35, formed of a transparent material, such as glass or a suitable plastic, the open end cf the cup 36 being closed by a coverl 31, preferably formed of a suitable plastic material, and the cup and cover are fitted and cemented together to seal against admission of air at their connection.

The cover 31 provides a water inlet chamber 38 which is in communication with the conduit 25 leading from the pressure regulator 24, and passages 39 and 49 extend respectively laterally and upwardly. The upper portion of the passage 45 is enlarged, and receives an orifice nozzle 4| having its free end extending into a valve chamber 42. Valve means 43 is provided to control flow of water outwardly from the orice provided by the orifice nozzle 4|, and as here shown, the valve means 43 comprises a exible diaphragm 44 extending across and closing the upper end of the valve chamber 42. The diaphragm 44 is tightly clamped, at its periphery, to the cover 31 by a valve cover 45 which is held down by screws, not shown. A flat flexible spring 46 underlies the diaphragm 44 and normally flexes the diaphragm upwardly and away from the adjacent terminal end of the oriiice nozzle 4|, and a central fiat-headed rivet 4| is passed through the flat spring, the diaphragm, and a washer above the diaphragm, the upper extremity of the rivet .stem being peened over to form a central button head. A valve screw 43, having a low pitch screw thread is screwed through a threaded aperture in the valve cover 45. The valve screw 48 is perfectly flat and smooth at its bottom terminal surface, and such surface engages the central button head of the rivet 41. When the valve screw 48 is turned down far enough it iexes the diaphragm downwardly so that the flat head of the rivet 41 accurately engages the orifice opening into the orice nozzle 4|, and closes passage therethrough.

On the upper end of the valve screw 48 a graduated dialed wheel 49 is secured, as shown. 'Rotation of this wheel opens or closes the valve, dependent upon the direction of rotation, approximately .00012 inch per graduation, and such increase, in the construction herein shown, corresponds to a change of approximately one gallon per day in the rate of water flow through the valve. Preferably, the dial graduations, seen in Figure 2, are numbered to indicate the rate of Water flow in gallons per day.

A movable indicator having a slotl 59 is anchoredin position on the valve cover 45 by means of a screw 5|. The indicator comprises a projection 52 positioned in the path of a stop lug 53 formed on the dial wheel 49 to limit the farthest open position of the dial wheel, and also to limit the tightness of valve closure. Without this limitation, the comparatively large diameter of the dial wheel 4S and very fine pitch of the thread of the valve screw 48 would permit the valve to be closed with considerable force, with the result that predetermined contact between the flat head of the rivet 41 and the adjacent part of the orifice nozzle 4| may be destroyed, and this would change the distance of the valve opening, and consequently change the rate of Water flow so that it would no longer correspond with the water flow rate indicated by the dial.

The diaphragm 44 itself must be flexible and rather soft, but by providing a relatively hard unyielding diaphragm center in the form of the flat head of the rivet 41, it is possible to have a flexible soft diaphragm with a center that will not expand, contract, or readily wear. With the valve screw 48 so adjusted that the flat rivet head is out of closing contact with respect to the adjacent terminal end of the orice nozzle 4|, water may flow from the valve chamber 42 and downwardly into the cup through an upright passage 54 formed in the cover 31.

The outlet of the water-feed control device 21 is positioned above the bottom of the cup 35, as indicated at 55, to provide a level of water in the bottom of the cup, and the conduit 28 is connected to the outlet 55. A screw-threaded aperture provided in the bottom of the cup 35 for purposes of draining the cup is normally closed by a screw plug 56.

The water-feed control device 21 is preferably mounted upon the wall of a room in the residence to be heated and humidified, and as here shown, the device 21 is enclosed in a housing which comprises a base 51 held to the Wall by means of screws or the like, and a sheet-metal case 58 is constructed and arranged to be snapped in position on the base 51. The case 58 is provided with a cut-out 59 to permit View of the water dripping, or owing, from the passage 54 in the cover 31 to the cup 36, and also to permit view of the level of the water in the cup. In this manner, a user may actually see whether or not water is being delivered to the cup 36y and in what quantities. This provides a means of checking whether or not the system is operating up to this point, as well as providing a means for showing the amount of water delivered to a subsequent part of the system.

Referring particularly to Figures 5 through rI, the water-feed device 29 comprises a cup 60, formed of transparent material, such as glass or a suitable plastic, the open end of the cup being closed by a cover` 6|, the connection being closely tted and cemented to seal against air entering at this point. The Water supply conduit 28 communicates with a chamber 62, formed in the cover El, and a passage 63 leads transversely from the chamber 62 to an upright drip or flow passage 64, the lower end of which delivers water to the cup 60.

The bottom of the cup 69 is formed with a screw-threaded aperture which receives a threaded fitting 65, connected to the drain conduit 30, and the fitting carries an overflow tube 66 extending upwardly inside of the cup 60. The overflow level in the cup may be varied by threading the tting 65 in a proper direction to extend the upper terminal end of the tube a greater or lesser to a point above the terminal end of the overflowtube 66 unseating the ball iioat valve 61 and permitting a drainage of water through the tube 66 and the communicating drain conduit Sii. yIn some cases, it is preferablato use an air trap formed in the drain conduit 3Q, such as an S-trap, or the `modiiiedform of suchtrap as by bending the drain conduit Safuponitself in the form of a circle as shown at 68, inrFigures 1 and 6, It will be appreciated thatI either or both the ball float valve 6l or the trap 68 may be used. n

The conduitv 3l communicates withthe interior of the cup 66 at a point spaced above the bottom of the cup but below the upper terminal edge of the overflow tube 66, as best seenin Figure.

any, sludge flowing through the drain conduit The water feed device 29 is preferably disposed exteriorly of the chamber 3d, and the conduit 3l extends from the device'ZQ, through a wall in the chamber 3 vand communicates with the interior of the evaporator pan 32, When thehumidifying system is used withy a hot air furnace, the water-feed device 2Q is disposed eXteriorly of the furnace casing, and the conduit extends through such casing and Ato the evaporator pan 32 located in the bonnet chamber.

The water-feed device 29 and the evaporator pan 32 are relatively so positioned that a common water level may be established therein. Accordingly, the level of water in the cup E@ will indicate the level of water in the evaporator pan 32. The level of water in the cup, and the drip or ow of water from the passage E4 are visible by reason of the transparency of the cupy 60. Thus, means are provided to check at this point, which may be at the furnace, whether or not that part of the system preceding the water feed device 29 is working, and further, a check is possible to determine whether vaporization of the water in the evaporator pan 32 is taking place, as well as to determine whether or not water is liowing through the conduit 3 l Sincethe overflow drain is connected to the water-feed device 2S, instead of tothe evaporator pan 32, in the event the `feed rate is too great compared with the evaporation rate, the excess water will not be delivered to the evaporator pan, but will be drained before it reaches the evaporator pan. Thus, the overflowing water will not carry away heat from the chamber 343, and likewise, the incoming relatively cold water will not reach the evaporator pan to reduce the temperature of the water therein.

Since most water contains certain substances, such as lime or the like, constant vaporization of the water from the evaporator pan 32, in at least certain instances, increases the concentration of such substances in the water in the evaporator pan, and in some cases this concentration approaches asludgy state. Therefore, it is highly desirable that the water, and other substances carried by it, in the evaporator pan, does not return to the cup 65. v

For this purpose, the equalizing conduit 35 is provided. As best seen in Figure 6. the conduit 35 is Ycarried by the cover 6l, and establishes cornmunication ybetween the inside of the cup 66 and the inside of the chamber 34, so that the air pressure in the cup 60 is always equal to the air pressure in the chamber 34. Otherwise, if the pressure in the chamber 3ft increased, as for instance when the air blower startedroperation,

such pressure would act on the relatively large' .watereiiposed by the evaporatorpan, and wouldforcethe Water in the evaporator 'pan back through'the conduit 3| and into the cup ,50.

rIhis is undesirable, not only because the substances. accompanying such water tends to .clog the conduit 3l, dirty the transparent cup 169, and stop 'up passages in the water-feed device '29, vbut also because the common Water level in `cup Eiland evaporator pan 32 will be unbalancedso that the water level in the cup 60 will ynot indicatethetrue level of the water in the evaporator pan. In some instances, the common ,water level is unbalanced to such extent that the nwaterlevel rises above the overflow tube 66 and flows through the` drain conduit 30. Additionwouldeventually,interfere with proper operation ofthe'oatvalve 61 or the air trap 68.

,user may accurately set the ow rate in a living room. of the house, and positively know that water is flowing, since he can Vsee' the ow and also the level of the water in the cup 36. Further, the system is closed and sealed against admissionof air pressure except that pressure :entering throughV the conduit 35. Since the cup .63 isl formed with air trap means, preventing. flowof. air. through the cup, practically no air lwill. enter the cup through the equalizer conduit 35, since an increase in air pressure in the chamber 34 will merely cause slight shifting of the air in the conduit 35, in the manner of a piston,

to compress the air in the cup 6! to a pressure equal to that in the chamber 34. Therefore, the air in the cups 35 and 6B is always fully saturated with moisture, preventing the drying of lime, or other. substance on the walls of the cups, and

thereby insuring that the visibility of the level and .ow of water in the cups will not be obscured.

In some instances, certain foreign mattermay pass the lter 23 and tend to obstruct passage of water through the system; for example, alum is used in some water purification plants to precipitate impurities in the water, and such substance, in certain cases, tends to form a ljelllike deposit which may obstruct water flow through small passages in the system. In such case, the purge lever 25 0f the pressure regulator 2B is turned to admit water under full pressure, and such surge of water effectively cleans all passages in the system of obstructions. Referring to Figure 1, it will be noted that the device 21 is above the device 29, and normally this is true since theV device 2 is usually mounted on the wall of `a living room of a house, whereas the device '29 is mounted preferably close to the chamber 3d, which in the case of a furnace, is close to or on the furnace casing.

However, the relative position of the devices may be changed, without departing from the invention and without sacrificing any advantages of the humidifying system. For example, Figure 8 illustrates a system comprising the parts used in the system shown in Figure 1, similar parts bearing the same reference numeral with the numerals in Figure 8 bearing the suX a.

Referring to Figure 8, the system therein disclosed illustrates a case where conditions require device 27a.

Figures 9 through 11 disclose a diierent embodiment of the invention, wherein a device delivering water to the evaporator pan is provided with means for controlling the water feed. Referring particularly to Figure 9, the humidication system comprises the circuit from the supply conduit 20o, through the shut-off valve 2lb, the water filter 23h, the pressure regulator 2417, the

conduit 2Gb, to a device 10 which controls the flow of water and also feeds such water to the evaporator pan 32h located in the chamber 341).

The device 19, referring particularly to Figures 10 and 11, comprises a cup 1I, formed of transparent material, such as glass or a suitable plastic, the upper open end of which is closed b-y a cover 12 provided with a transverse bore 13 connected to the conduit 26D. The bore 13 communicates with an upright passage 14, formed in the cover 12, the upper end of which is enlarged to receive an orice nozzle 15 which has its upper part extending into a valve chamber 116. A diaphragm valve 11 closes the chamber 16, and it is held in place by a valve cover 18, the latter having connection with the cover 12 by means of screws (not shown). Threaded in a screwthreaded aperture in the valve cover 18 is an adjustment screw 19 connected to a dial wheel 89. The dial wheel has a lug 8| cooperating with an adjustable stop 82, the construction being similar to the construction shown in Figures 2 and 3. As before, the screw 19 bears against the peened end of a rivet 83, rotation of the screw providing for adjustment of the diaphragm valve 11 relative to the orice outlet of the orice nozzle 15.

The bottom of the cup 1I is formed with a screw-threaded opening into which fits a tting 84 which carries an overflow tube 85. The inner terminal end of the tube 85 is normally closed by a ball check valve 85 adapted to be unseated by the water when the level reaches above th'e inner terminal end of the tube 85, to permit draining of water through the drain conduit 3017, but sealing the tube 85 against entrance of air. If desired, the drain conduit 30h may be bent to form an air trap 98h, and either or both the ball check valve 85 or the trap 58h may be used.

The cup 1I has a conduit 81, spaced upwardly from its bottom a slight distance, and extending through the wall of the chamber 34h, to the evaporator pan 32h, the cup 1| and evaporator pan 32h being relatively so disposed that a common water level may be established therein. The cover 12 has a passage 83 communicating with the interior of the cup 1 I, and an equalizer conduit S9 establishes air pressure communication between the interior of th'e cup 'II and the chamberfdb. The humidication system and apparatus shown in Figures 9 through l1 operates in the manner,

Vand has the advantages heretofore pointed out,

this system differing only in that the device 'I8 not only feeds water to the evaporator pan, but also has means to regulate the amount of water entering the cup 'I I.

The humidication system shown in Figure 12 is similar to the system shown in Figure 9, with the exception that a control device 90 is substituted for the control device 10. Accordingly, like parts of the system will be given like reference numerals, with the exception that the suix c will be inserted in place of the suix b.

As seen in Figures 12 and 13, the conduit 25e leads to the inlet of the device 99, which in this instance embodies a iioat controlled valve for regulating ow of liquid. The device 90, shown in detail in Figures 13 through 16, comprises a cup 9|, formed of transparent material, such as glass or a suitable plastic. The upper open end of the cup 9| is closed by a cover 92 which is fitted and sealed tightly at the joint, to seal against entrance of air at this point. The conduit 26o is threaded to an inlet tting 93, secured to the cover by screws 94, and water from the conduit 25e passes downwardly through a passage 95, formed in the tting 93, and through a passage in the orifice nozzle 96, the lower end of which forms a valve seat. From the orice nozzle, the water passes into an annular space 91, formed by the tting 93 and the cover 92, and then upwardly through a passage 98 which leads to a tube 99, the terminal end of which extends through the cover 92 and terminates inwardly of the cup 9|, so that the water dripping or flowing from such terminal end is visible from the exterior of the cup.

Within the sealed chamber formed by th'e cup 9| and the cover 92, is a float |00, having an upright post Il, at one side, to which one end of parallel levers |02 are pivoted, the opposite ends being pivoted in a post |03 which is rigidly secured to the cover 92, as best shown in Figure 13. The movement of the iioat |09 is conveyed to a plunger |04, which slides in an aperture formed in the cover 92, by means of a link |05 and lever |56. The lever |06 is fulcrumed at |01, and has a pivotal connection with the plunger |04, as best seen at I 08 in Figure 13.

A diaphragm |09, clamped between the tting 93 and the cover 92, is movable within the annular space 91, and is cooperable with the valve seat formed by the orifice nozzle 98 to control flow of water through such nozzle. Upward movement of the plunger |04 exes the central portion of the diaphragm |09 in a direction to contact the valve seat and close passage through the orice nozzle. It will be appreciated that the lever mechanism greatly increases the lifting force of the float, so that suiicient force is provided to lift the diaphragm |09 to closed position against any usual water pressure.

To provide for adjustment of the valve-closing action of the oat |00, th'e fulcrum |01 of the lever |06 is in the form of a short lever I|0, in turn pivotally connected to one end of an arm III which is pivoted intermediate its ends to a stud |I2 extending downwardly from the cover 92. The opposite end of the arm |II is formed to straddle the post |03. The post I 03 carries a xed collar II4 which serves as a base for a compression spring II5. The spring |I5 is arranged to urge the adjacent end of the arm III upwardly against the bottom of a regulating screw IIS which is threaded in a threaded aperture formed in the cover 92. The upper end of the screw IIS extends outwardly of the cover 92 and has secured thereto a lever I1 by means 0f which the screw IIB may be rotated. Movement of the lever I|1 causes rotation of the screw IIE, causing the bottom end of the screw to move the arm II I about its fulcrum point on the stud II2. Rotation of the screw IIG will move th'e lever III and cause a shifting of the short lever, thus changing the pivot point |01 of the lever |06, and consequently changing the closing point of the diaphragm valve I 09. The exterior surface v ofthe cover 92 is provided with spaced-apart lugs IIS, which limit movement of the lever II1, the construction herein disclosed being such that rotation of the screw H6 between the limits dened by the lugs H8 is sufficient to provide for practical adjustment of the closing point of the diaphragm valve |09.

Water is conducted from the cup 9| to the evaporator pan 32C by means of the conduit l I9, leading from a point spaced upwardly of the lower end of the cup 9i. As best seen in Figure 12, the device 90 and the evaporator pan 32e are relatively so disposed that a common liquid level may be established therein. An equalizer conduit l2!! leads from the upper end of the cup 9| to the chamber Stic, so that the pressure in the cup 9i is at all times equal to the pressure in the chamber Sc, thus providing that the common liquid level is not unbalanced.

Extending from the cup 9i, at a predetermined level, is an overflow fitting i2l, containing a ball check valve l22. Normally, the ball check valve 22 engages a seat formed in the fitting |2I, but if the Water level rises to a point where water flows through the iitting IZI, the ball will float and rise from its seat, permitting drainage of water through the drain tube 30o. The drain tube 30e may be bent in the form of an air trap 68e, and either or both the ball check valve |22 and trap 68C may be used to prevent admission of air` to the interior of the cup 9 l.

In the embodiment 'shown in Figures 12 through 16, the level in the evaporator'pan 32e and the like level in the cup BI is maintained by the float l, adjustment of float settings being possible by manipulation of the lever l l?. In all other respects, the system therein disclosed provides the advantages hereinbefore pointed out. As before, the cup 9i is sealed againstl air flow therethrough, and accordingly the air in the cup 9| is always in fully saturated condition. This is very desirable in the construction shown in Figures l2 through 16, since lime and like substances cannot dry within the cup 9| to form a crust interfering with proper operation of the valve mechanism.

From the foregoing it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention, and it also will be apparent to those skilled in the Vart that the embodiments herein described may be variously changed and modiiied, without departf ing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specically described; hence it will be appreciated that the herein disclosed embodiments are illustrative only, and that my invention is not limited thereto.

I claim:

l. In combination: a chamber through which air is adapted to move; an evaporator pan, disposed within said chamber, for adding moisture to the air in said chamber; a receptacle disposed exteriorly of said chamber and having liquid inlet means; liquid supply means, from a source of liquid, having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being relatively so disposed that a common liquid level may be established therein leaving a space above the liquid level in said receptacle; means, having atmospherically sealed connection with said receptacle, for establishing liquid communication between said receptacle and said evaporator pan and for establishing air communication between said space and said chamber to equalize air pressure on the liquid in said receptacle and the liquid in said pan to prevent unbalancing of the common liquid level in said receptacle and said chamber; and said receptacle having liquid overflow outlet means for limiting the maximum height of said common liquid level, the entrance to said over- 10. flow outlet means from said receptacle being at a place in said receptacle which can be exposed to the air in said space by predetermined reduction of the height of said common liquid level; and said overow outlet means including air seal means constructed and arranged to permit flow of liquid from said receptacle into said entrance and through said overflow outlet means to at'- mosphere but eiiec'tively to seal the inside of said receptacle and atmosphere against relative air communication through said overilow outlet means. 2. In combination: a, chamber through which air is adapted to move; an evaporator pan,v` disposed within said chamber, for adding moisture to the air in'said chamber; a receptacle disposed exteriorly oi" said chamber and having liquid inlet means; liquid supply means, 'from a source of liquid having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being'r'elatively sodisposed that a common liquid 'level may be established therein leaving aV space above the liquid level in said receptacle; vfloat controlled valve means `constructed and arranged to control'the flow of liquid from the source to said receptacle, dependentA upon the levelv oi the liquidY in -said receptacle means, having atmospherically sealedV connection with said receptacle, forestablishing liquid communication between said receptacle and said evaporator pan and vfor establishing" air communication between said space and said chamber to equalize air pressure on the liquid'in said receptacle and the liquid'in said pan toY prevent unbalancing of the common liquid level "said rceptacle and said chamber; Vand said receptacle having'liquid overflow outlet means'for limiting the maximum heightl of said common liquid level; the entrance to said overflow 'niitlet'ineansV from said receptacle being at a place in said receptacle which can be exposed tov the air in said space by predetermined reduction of the height of said common` liquid level; yand said voverflow outlet means including air seal means constructed and -arranged to permit ilow of liquid Vfrom said receptacle into said entrance and through said overflow outlet means to atmosphere but efrfectively to seal the inside of said receptacle and atmosphere against relative air Ycommunication through said overilow outlet means. l l

3. In combination: a chamber through which air is adapted to move; an evaporator pan, dirsposed within said chamber, for adding moisture to the air in said chamber; a receptacle disposed exteriorly of said chamber and having liquid inlet means; liquid supply means, from a source of liquid, having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being relatively so disposed that a common liquid llevel may be estabilished therein leaving va space above the liquid level in said receptacle; said liquid vsupply means including manually adjustable valve means for adjusting the ilow of liquid from the source to the receptacle; means, having atmospherically sealed connection with -said receptacle, for establishing liquid communication between said receptacle and said evaporator pan and for establishing air colmmunicationbetween said space and said chamber to equalize air pressure on the liquid in said receptacle and the liquid in said pan to prevent unbalancing of the common liquid level in said receptacle and said chamber; and said receptacle having i liquid overiiow outlet means for limiting Athe maximum height oi said common liquid level, the entrance to said overiiow outlet means from said receptacle being at a place in said receptacle which can be exposed to the air in said space by predetermined reduction of the height of said common liquid level; and said overflow outlet means including air seal means constructed and arranged to permit flow of liquid from said receptacle into said entrance and through said overflow outlet means to atmosphere but effectively to seal the inside osaid receptacle and atmosphere against relative air communication through said overflow outlet means.

4. In combination: a chamber throughwhich air is adapted to move; an evaporator pan, disposed within said chamber, for -adding moisture to the air in said chamber; a receptacle disposed exteriorly of said chamber and having liquid inlet means, said receptacle being so constructed and arranged that the level of the liquid therein is visible; liquid supply means, from a source of liquid, having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being relatively so disposed that a common liquid level may be established therein leaving a space above the liquid level in said receptacle; said liquid supply system including valve means and means rendering visible the liquid allowed to flow through said valve means; means, having atmospherically sealed connection with said receptacle, for establishing liquid communication between said receptacle and said evaporator pan and for establishing air communication between said space and said chamber to equalize air pressure on the liquid in said receptacle and the liquid in said pan to prevent unbalancing of the common liquid level in said receptacle'and said chamber; and said receptacle having liquid overow outlet means for limiting the maximum height of said common liquid level, the entrance to said overow outlet means from said receptacle being at a place in said receptacle which can be exposed to the air in said space by predetermined reduction of the height of said common liquid level; and said overflow outlet means including air seal means constructed and arranged to permit flow of liquid from said receptacle into said entrance and through said overflow outlet means to atmosphere but effectively to seal the inside of said receptacle and atmosphere against relative air communication through said overflow outlet means.

5. In combination: a chamber through which air is adapted to move; an evaporator pan disposed within said chamber, for adding moisture to the air in said chamber; a receptacle disposed eXteriorly of said chamber and having liquid inlet means; liquid supply means, from a source of liquid, having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being relatively so disposed that a. common liquid level may be established therein leaving a space above the liquid level in said receptacle; said receptacle having liquid feed outlet means; conduit means having atmospherically sealed connection with said liquid feed outlet means and constructed and arranged to establish liquid communication between said receptacle and said evaporator pan; conduit means connected to said space and to said chamber, constructed and arranged to equalize air pressure on the liquid in said receptacle and the liquid in said evaporator pan, to prevent unbalancing of the common liquid level in said receptacle and said pan; said receptacle having liquid overflow outlet means for limiting the maximum 'height of said common liquid level, the entrance to said overow outlet means from said receptacle being at a place in said receptacle above said liquid feed outlet means; and said liquid overow outlet means including air seal means constructed and arranged to permit flow of liquid from said receptacle into said entrance and through said overow outlet means to atmosphere but eiectively to seal the inside of said receptacle and atmosphere against relative air communication through said overow outlet means.

6. In combination: a chamber through which air is adapted to move; intermittently operable blower means, for intermittently forcing air through said chamber; an evaporator pan, disposed Within said chamber, for adding moisture to the air in said chamber; a receptacle disposed exteriorly of said chamber and having liquid inlet means; liquid supply means, from a source of liquid, having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being relatively so disposed that a common liquid level may be established therein leaving a space above the liquid level in said receptacle; means, having atmospherically sealed connection with said receptacle, for establishing liquid communication between said receptacle and said evaporator pan and for establishing air communication between said space and said chamber to equalize air pressure on the liquid in said receptacle and the liquid in said pan to prevent unbalancing of the common liquid level in said receptacle and said chamber when said blower means is operating; said receptacle having liquid overflow outlet means for limiting the maximum height of common liquid level in said receptacle, the entrance to said overflow outlet means from said receptacle being at a place in said receptacle which can be exposed to the air in said space by predetermined reduction of the height of said common liquid level; and said overow outlet means including air seal means constructed and arranged to permit flow of liquid from said receptacle into said entrance and through said overflow outlet means but effectively to seal the inside of said receptacle to prevent escape of air from said receptacle through said overflow outlet means when said blower means is operating.

7. In combination: a chamber through which air is adapted to move; intermittently operable blower means, for intermittently forcing air through said chamber; an evaporator pan disposed within said chamber, for adding moisture to the air in said chamber; a receptacle disposed exteriorly of said chamber and having liquid inlet means; liquid supply means, from a source of liquid, having atmospherically sealed connection with said liquid inlet means; said receptacle and said evaporator pan being relatively so disposed that a common liquid level may be established therein leaving a space above the liquid level in said receptacle; said receptacle having liquid feed outlet means; conduit means having atmospherically sealed connection with said liquid feed outlet means and constructed and arranged to establish liquid communication between said receptacle and said evaporator pan; conduit means connected to said space and to said chamber, constructed and arranged to equalize air pressure on the liquid in said receptacle and the liquid in said evaporator pan, to prevent unbalancing of the common liquid level in said receptacle and said pan when said blower means is opi3' erating; said receptacle having liquidA overflow outlet means for limiting the maximum height of said common liquid level, the entrance to said overflow outlet means from said receptacle being at a place in said receptacle above said liquid feed outlet means; and said liquid overow outlet means including air seal means constructed and arranged to permit flow of liquidfrom said receptacle into said entrance and through said overiiow outlet means but eiiectively to sealthe inside oi said receptacle to prevent escape of air from said receptacle through said overflowoutlet means when said blower means is operating.

8. In combination: a chamber, through which air is adapted to move; an evaporator pan, dis,- posed within said chamber, for adding moisture to the air in said chamber; and a liquid supply system, for supplying liquid to said evaporator pan, comprising a closed housing, and liquid supply means, from a source of liquid, having atmospherically sealed connection with said housing, and conduit means establishing liquid communication between the interior of said housing and said evaporator pan, said housing and said evaporatorY pan being so constructed and arranged that a single, common liquid level may be established therein, and liquid overflow means having atmospherically sealed connectionk with said housing and constructed and arranged to prev-ent said single, common liquid level to rise beyond a predetermined level short of overflowm ing said evaporator pan and also short of completely lling the interior ofv said housing; and means providing air pressure communication between the interior oi said housing, above said I single liquid level, and said chamber only, equalizing the air pressure on the liquid within said housing and said evaporator pan, and preventing unbalancing of said common liquid level.

9. In combination: evaporating means, inclu'k ing a pan for containing liquid, constructed and arranged for adding moisture to air in an air circulation chamber; conduit means, extending from said pan to a source of liquid supply; and first and second closed housings, each forming a liquid chamber, interposed in said conduit means in spacedapart relation; said rst housing having means for establishing a liquid level below the top and above the bottom of its chamber and below the top and above the bottom of said pan; and said second housing being nearer the source of liquid than said first housing and having means for establishing a liquid level below the top and above the bottom of the chamber of said second housing,

l0. In combination: evaporating means, including a pan for containing liquid, constructed and arranged for adding moisture to air in an air circulation chamber; conduit means, extending from said pan to a source of liquid supply; and first and second closed housings, each forming a liquid chamber, interposed in said conduit means in spaced-apart relation; said first housing having means for establishing a liquid level below the top and above the bottom of its chamber and below the top and above the bottom of said pan; and said second housing being nearer the source of liquid than said rst housing and having means for establishing a liquid level below the top and above the bottom of the chamber of said second housing; each of said housings having a liquid inlet above the liquid level in the respective chamber and constructed and arranged so that liquid falls through space above the respective liquid level; and each housing having means constructed andarrangedvto permit ViewAx second, conduit leading from the upper portionofsaid housing to the atmospheresurrounding said reservoir, and an overilow outlet Yleading from the.

interior ci saidhousing at a pointv aboves'aid outletcondut.

12. AV device for feedingl liquid to evaporator means the air surrounding which may be atea pressure diiierent from atmospheric pressure, comprising; a receptacle providing a chamber,

said chamber having inanupper porticnthere'of' liquidfinlet means constructed and arranged. for atmosp-herically sea-led connection to ac source ci' liquid, and. having in a lower. portion thereof liquid discharge outlet meansY constructed andl arranged for atmospherically. sealed connection to feed liquid to said evaporator means, and hav! ing liquid overflow outlet means communieating with said chamber at a level above said discharge outlet, and having atmospherically sealed inlet. means communicatingV with the space in said chamber above said level and constructed and arranged forVVV connection to communicate with the air surrounding said evaporator means.

13. A device for feeding liquid to evaporator means the air surrounding which may be at a pressure diiferent from atmospheric pressure, comprising: a receptacle providinga chamber,said chamber having in an upper portion thereof liquid inlet means constructed and arranged for atm mospherically sealed connection to a source of liquid, and having in a lower portion thereof liquid discharge outlet means constructed andy arranged for atmospherically sealed connection to feed liquid tosaid evaporator means, and. having liquid overflow outlet means communicating with said chamber at a level above said discharge outlet, and having atmospherically sealed inlet means communicating with the space in said chamber aboveV said level and constructed and arranged for connection to communicate with the air surrounding said evaporator means; and air seal means constructed and arranged to permit flow of liquid from said chamber through said outlet means to atmosphere but eilectively to seal the inside of said chamber and atmosphere against relative air communication through said outlet means.

14. A device for feeding, liquid. to evaporator means the` air surrounding which may be at a pressure higher than atmospheric pressure, comprising: a receptacle providing a chamber, said chamber having in an upper portion thereof liquid inlet means constructed and arranged for atmospherically sealed connection toa source of liquid, and having in a lower portion thereof discharge outlet means constructed and arranged for atmospherically sealed connection to feed liquid to said evaporator means, and having liquid overflow means communicating with said chamber at a. level above said discharge outlet, and having atmospherically sealed inlet means communieating with the space in said chamber above said level and constructed and arranged for connection to communicate with the air surrounding said evaporator means; and air seal means constructed and arranged to permit flow of liquid from said chamber through said outlet means to atmosphere but effectively to seal the inside of said chamber against escape of air therefrom through said outlet means.

15. A liquid feed device, comprising: a closed housing, adapted to receive liquid, having a liquid inlet adjacent its top and a liquid outlet adjacent its bottom, and having a drain outlet disposed intermediate said liquid inlet and said liquid outlet, said drain outlet being constructed and arranged to limit the liquid in said housing to a predetermined level short of said liquid inlet but above said liquid outlet so that liquid from said liquid inlet falls through space to the liquid in said housing; conduit means, providing communication of said space with an air space external to said housing; means, preventing ow of air through said drain outlet to said space in said housing; and said conduit means and said liquid outlet being adapted for subjection to like air pressure from said air space external to said housing, so that if the liquid level in said housing falls below said liquid outlet, ilow of air through said housing is precluded.

16. A liquid feed device, comprising: a housing, for receiving liquid, having a liquid inlet adjacent its top and having a liquid delivery opening and liquid overow outlet means, limiting the liquid in said housing to a predetermined level above said liquid delivery opening and short of the top of said housing, providing an air space between said top and the level of the liquid; said housing having means providing for communication of said air space with an air space external to said housing but being closed to communication with air at all other places including at said liquid overflow outlet means so that air flow through said housing is precluded.

17. In combination: a chamber, through which air moves; an evaporator pan, disposed within said chamber, for adding moisture to the air in said chamber; a receptacle, connectable to a source of liquid, and disposed exteriorly of said chamber; conduit means, establishing liquid communioation between said receptacle and said evaporator pan, said receptacle and said evaporator pan being relatively so disposed that a common liquid level may be established therein; said receptacle having liquid overiiow outlet means for limiting the liquid level therein to a predetermined level; means precluding the flow of air through said overflow outlet means; and means, constructed and arranged to equalize air pressure on the liquid in said receptacle and the liquid in said evaporator pan, preventing unbalancing of said common liquid level.

18. In combination: a chamber, through which air moves and in which the air pressure may be above atmospheric pressure; an evaporator receptacle, disposed within said chamber, and adapted to contain liquid open to the air in said chamber for adding moisture to such air; a

16 liquid feed receptacle, connectable to a source of liquid, and disposed exteriorly of said chamber; conduit means, establishing liquid communication between said liquid feed receptacle and said evaporator receptacle, said liquid feed receptacle and said evaporator receptacle being relatively so disposed that a common liquid level may be established therein; said feed receptacle having liquid overflow outlet means for limiting the liquid level therein to a predetermined level; means precluding the flow of air through said overow outlet means; and means, constructed and arranged to equalize the air pressure on the liquid in said liquid feed receptacle and said evaporator receptacle, preventing a backing up of liquid from said evaporating receptacle to said liquid feed receptacle when said air pressure is above atmospheric pressure.

OTTO J. KUENHOLD, SR.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 424,596 Burns Apr. 1, 1890 1,623,313 Horton Apr. 5, 1927 907,504 Kane Dec. 22, 1908 914,978 Ridgway Mar. 9, 1909 1,946,734 De Lin Feb, 13, 1934 855,167 Essex May 28, 1907 1,425,608 Sallada Aug. 15, 1922 1,458,549 Sallada June 12, 1923 752,577 McDougal Feb. 16, 1904 1,259,761 McMillan Mar, 19, 1918 1,676,763 Anetsberger July 10, 1928 1,473,676 Hendrix Nov. 13, 1923 1,654,209 Buehrer Dec. 27, 1927 628,581 Grosswyler July 1l, 1899 1,234,625 Chapman July 24, 1917 1,865,870 MacLean July 5, 1932 1,724,279 Gruber Aug, 13, 1929 287,369 Edwards Oct. 23, 1883 2,134,597 Borden Oct. 25, 1938 1,172,578 Brinkman Feb. 22, 1916 1,611,505 Barnhart Dec. 2l, 1926 1,206,081 Becker et al Nov. 26, 1916 1,223,021 Allen Apr. 17, 1917 771,399 Soderstrom Oct, 4, 1904 1,925,601 Pfening Sept. 5, 1933 2,155,070 Woolley Apr. 18, 1939 1,016,521 Redeker Feb. 6, 1912 1,802,590 Waterman Apr. 28, 1931 1,974,816 Johnson Sept. 25, 1934 2,019,628 Ostermann Nov. 5, 1935 1,087,875 Garrecht Feb. 17, 1914 1,380,321 Liebold May 31, 1921 1,389,804 Wrenn Sept. 6, 1921 FOREIGN PATENTS Number Country Date 742,365 France 1932 

